what is the heat flow if area and thermal conductivity and temperature difference is given?

Question

 A plane wall is 25 cm thick with an area of 1 m², and has a thermal conductivity of 0.5W/mk. If a temperature difference of  60°C is imposed across it, what is the heat flow?                    (IES-05)

a. 120W                       b. 140W

c. 160W                       d. 180W